const Koa = require('koa')
const app = new Koa()

const one = (ctx, next) => {
    console.log(1);
    next()
    console.log(2);
}

const two = (ctx, next) => {
    console.log(3);
    next()
    console.log(4);
}

const three = (ctx, next) => {
    console.log(5);
    next()
    console.log(6);
}

app.use(one)
.use(two)
.use(three)

app.listen(3000, ()=> {
    console.log('listening on 3000');
})